肾硬化大鼠肾小球细胞增殖和凋亡的研究

Glomerular cell proliferation and apoptosis in experimental glomerulo sclerosis

目的:评估实验性肾硬化大鼠肾小球细胞增殖和凋亡的消长关系,探讨肾小球细胞凋亡在肾小球硬化进程中的可能作用。方法:单侧肾摘除加重复静注阿霉素诱导实验组大鼠加速肾硬化形成,对照组则以假手术和生理盐水静脉注射代替。在实验第4周、8周和12周测定肾功能,并于第12周测定大鼠平均动脉压和肾小球平均体积。脱氧核苷酸末端转移酶介导的缺口末端标记法(TUNEL法)和免疫组化法原位检测肾小球细胞凋亡指数和增殖指数。结果:实验组大鼠肾功能逐渐恶化,平均动脉压显著升高,组织病理学检查显示局灶节段性肾硬化形成。实验组各时间点增殖指数和调亡指数明显升高(P<0.01),且均于12周达高峰,但实验组4周和8周前者明显高于后者(3.15±0.55vs 1.92±0.52,P<0.01;4.42±0.60vs 3.50±0.684,P<0.05),而12周时后者则显著高于前者(10.03±1.67 vs 8.08±0.70,P<0.05)。直线相关分析显示实验组肾小球中凋亡指数与增殖指数呈密切正相关(P<0.02),肾功能恶化与肾小球细胞凋亡指数之间存在明显正相关(P<0.05)。结论:实验性肾硬化大鼠中肾小球细胞调亡是清除过度增殖细胞的一种机制,但过度的细胞凋亡又可能导致肾小球内固有细胞数减少,加重肾小球硬化进展。

Objective: To evaluate the regression of glomerular cell proliferation and apoptosis in experimental glomerulosclerosis. Methods: The uninephrectomy with twice intravenous adriamycin injection model of chronic glomerulosclerosis was studied in adult male Wistar rats. The renal function, glomerular cell proliferation and apoptosis were examined at 4,8 and 12 weeks after the first intravenous adriamycin injection. Mean arterial pressure and average glomerular area ( AG ) and volume ( VG) were examined. Apoptosis was assessed by in situ dUTP biotin nick - end labeling method . Proliferation was determined according to proliferation cell nuclear antigen ( PCNA) by immunohistochemistry. Results:-Our results showed that the number of apoptotic glomerular cells gradually increased peaking at 12 weeks with the progression of glomerulosclerosis (apoptotic cells 1.92 ±0.52, 3. 50 ± 0. 68,10.03 ± 1.67 at week 4, 8and 12 ) . Parallel changes in the number of PCNA positive glomerular cells were observed (prolif erative cells 3.15 ± 0.55,4.42 ± 0.60,8.08 ± 0.70 at week 4, 8 and 12) although the increase in apoptosis was greater than that in proliferation at week 12. Conclusion: The results suggested that excessive apoptosis may decrease the number of glomerular cells which is likely to be involved in the progression of glomerulosclerosis although proliferlting glomerular cells in the early phase can be regrdssed by apoptosis.